re: How to tell a friend their breath stinks really bad?

Surprised this hasn't been mentioned yet:

Tell friend to look into pulling out tonsil stones if it's that persistent and bad. No doubt they're in there.

They're in a lot of people's mouths. Some sick stuff. Google is not your friend. You've been warned.

I wouldn't think twice about saying something. frick, I told the chick working at Verizon her breath stunk last week

People pretend like they're pissed, but wouldn't you rather not walk around stinking up the place?

Give them a nickname like "dragon breath" and only refer to them by the nickname until the problem is solved.